Generally speaking, such microelectronic devices as MLCCs are chosen after the failure/quality test at a final process in their manufacturing procedure. For the test, the electric devices are aligned on a test plate, and a probe makes contact therewith.
FIG. 1A shows a section of an electric device tester, 1B being a plan view of the test plate of FIG. 1A with the microelectronic devices mounted. As shown in these drawings, the microelectronic device tester includes: a test plate 11 in which recesses 15 are formed on the circumference of a disk at predetermined intervals to receive microelectronic devices 16 therein; a motor 12 for rotating test plate 11; a probe 13 installed at its measurement location and making contact with one of the microelectronic devices 16; and a meter 14 for measuring microelectronic devices 16 through probe 13.
In order to measure microelectronic devices, they are first aligned in recesses 15 formed on the disk-shaped test plate. Motor 12 is then driven to rotate test plate 11. When test plate 11 rotates for devices 16 to reach their test locations, motor 12 stops, and then probe 13 makes contact with devices 16 reached. Meter 14 measures devices 16 received in recesses 15 of test plate 11 through probe 13 connected to devices 16.
FIG. 2 is a block diagram of a conventional tester for microelectronic devices. This tester contains: a probe 23 installed at its measurement location to make contact with the devices 22 accommodated in test plate 21's recesses; an RLC meter 24 for measuring devices 22 through probe 23; a flash tester 25 for checking the insulation of devices 22 by applying a high voltage thereto; a motor controller 26 for controlling the rotation speed and position of a motor which rotates test plate 21; a monitor 27 for displaying the devices' measurement status and information required; and a microcomputer 28 for outputting a control signal which controls the motor's speed and location so that test plate 25 places each devices 22 at the measurement location, and for comparing the measurement result of RLC meter 24 and flash tester 25 with reference data in order to find out the devices' quality or failure.
FIG. 3A shows a circumferential section of the test plate for explaining the operation of the conventional tester. In this drawing recesses 32 are formed on the circumference of test plate 31 at a predetermined interval, each containing microelectronic device 33. When the motor is driven to rotate the test plate, it moves by one step from the current recess to the next, and then the motor stops. In this situation a device 33 to be measured stops at the measurement location, and the probe installed thereat makes contact with the device 33 in order to check its quality or failure.
FIG. 3B is a timing diagram of the operation of the conventional tester for microelectronic devices, showing the time period taken for the tester's movement and measurement with respect to the time axis. According to FIG. 3B, the movement time is taken longer than the measurement time because the test plate rotates only by one step between the recesses containing the microelectronic devices to thereby measure a single device at the location moved. This effect does not afford a great amount of products.